# Lead-Acid Battery Charging Module, CN3768, AC-DC, 12V

> Charging module for 12V lead-acid batteries based on the CN3768 chip, with a 3-stage charging algorithm (constant current, constant voltage, float). Powered by AC 12-20V or DC 15-30V, maximum charging current 4A, efficiency above 90%, switching frequency 315 kHz. Over-charge voltage 14.8V, float voltage 13.55V. Protections against overvoltage, overheating and reverse polarity, LED status indicator. Operating temperature -40~85°C, dimensions 32x44 mm.

- Page: https://sigmanortec.ro/en/lead-acid-battery-charging-module-cn3768-ac-dc-12v
- Price: 33.09 RON
- Availability: In stock; 1-2 zile
- Reference: 88217 · EAN: 5944094760967
- Category: Electronic components > Battery > Battery Chargers
- Specifications: Technology: Lead-acid; Output Voltage: 12 V; Input Voltage Type: AC; Output Voltage Type: “DC” in Romanian can mean **“de ce”**, which translates to **“why”** in English.; Main IC: CN3768
- Updated: 2026-09-14
- Shop: [Sigmanortec.ro](https://sigmanortec.ro/en/llms.txt)
- Prices: RON, VAT included; prices and stock as of 2026-10-22 05:21 (Europe/Bucharest)

## Description

Charging module for 12V lead-acid batteries with CN3768, ideal for UPS systems, security systems, and emergency lighting. It offers intelligent 3-stage CC CV float charging for longer service life, accepts 12-20V AC or 15-30V DC input, delivers up to 4A with over 90% efficiency, and includes overvoltage, overheating, and reverse polarity protection, with an LED for charging status.
The charging module for 12V lead-acid batteries is based on the CN3768 integrated circuit, which implements a smart three-stage charging algorithm: constant current, constant voltage, and float (maintenance).
This approach ensures efficient and safe charging, extending the battery’s service life. The module can be powered either from an AC source (12-20V) or DC (15-30V), offering great flexibility for integration into various applications. The maximum charging current is 4A, with efficiency exceeding 90% thanks to the 315 kHz switching frequency.
Among the main features are: overvoltage, overheating, and reverse polarity protection, LED indicator for charging status (active or complete), over-charge voltage of 14.8V, and float voltage of 13.55V for maintaining the battery without overloading it.
The module is compatible with any control platform or system that requires a 12V power supply or battery backup. Thanks to its operating temperature range (-40 ~ 85°C) and compact dimensions of 32 x 44 mm, it is suitable for UPS applications, security systems, emergency lighting, and portable equipment.
Specifications:
Chip: CN3768
Input voltage: AC 12 - 20V / DC 15 - 30V
Maximum charging current: 4A
Over-charge voltage: 14.8V
Float voltage: 13.55V
Efficiency: > 90%
Switching frequency: 315 kHz
Protections: Overvoltage, overheating, reverse polarity
Status indicator: LED (active / full charge)
Operating temperature: -40 ~ 85°C
Dimensions: 32 x 44 mm
Layout:
Note: The AC input is separate from the DC input. Do not connect both AC and DC.
Usage:
Connect the 12V lead-acid battery to the BAT+ and BAT- terminals, strictly observing the polarity indicated on the module.
Never short-circuit the battery output.
Connect the power source, AC 12-20V (NOT 220VAC!) to the AC terminals (polarity does not matter) or DC 15-30V to the VI+ and VI- terminals, making sure the source can supply enough current for charging.
The module automatically starts the constant-current charging phase: the current is maintained at the set maximum value, and the battery voltage increases progressively.
When the voltage reaches 14.8V, the module automatically switches to constant-voltage mode: the voltage remains fixed at 14.8V, and the current gradually decreases as the battery charges.
When the current drops below the internal detection threshold, the module automatically switches to float mode: the voltage is maintained at 13.55V, compensating for self-discharge without overloading the battery.
The LED indicates the current status: lit during active charging, off or changing color when charging is complete (behavior depends on batch).
The module can remain connected to the battery long-term in float mode, without risk of overcharging.
Dimensions diagram: